Psych Congress Opens With Deep Dive Into Psychedelics

October 25, 2018

Robin Carhart-Harris, PhD
    Robin Carhart-Harris, PhD

ORLANDO, Fla.—The opening session of the 31st annual Psych Congress gave attendees a detailed view of the ways in which psychedelic compounds such as psilocybin and LSD affect the brain and how they could be used in psychiatric practice.

The hourlong talk was delivered by Robin Carhart-Harris, PhD, the head of psychedelic research for the center for neuropsychopharmacology at Imperial College London in England.

Psych Congress cochair Charles L. Raison, MD, who is also involved with psychedelic research, described Dr. Carhart-Harris as a “spectacular unique leader in this emerging world.”

“Robin has really been the leading light for the last more than half a decade, looking not just at what [psychedelics] mean clinically but what’s really important, looking much more at this translational science question of how can it be that something that people take one time can produce these long-term effects,” Dr. Raison said.

Through research involving neuroimaging and other techniques, Dr. Carhart-Harris has used psychedelics as “probes into, in many ways, what it means to be human,” he added.

“If you induce these profound experiences in a person’s consciousness, that digs very deeply into what a lot of us cherish in terms of what it means to be human, to have certain perceptions, to have certain feelings,” Dr. Raison said.

“The ability to study those, to induce those and look before and after, because the drugs serve as a probe into that world, is I think one of the greatest and most remarkable technologies that we have at our disposal currently to understand how the brain, the mind, the heart, the spirit all come together.”

Q&A With Dr. Carhart-Harris: Uncovering the Therapeutic Potential of Psychedelics

Dr. Carhart-Harris also highlighted the fact that psychedelics seem to have enduring outcomes after just a single administration.

“As a drug model, that’s kind of unheard of, so what’s going on here?” he said.

Dr. Carhart-Harris has been studying the use of psychedelics in humans since 2008, including as a depression treatment since 2011. For the last 2 years, he has been working to develop psilocybin as a medicine.

He said widespread interest in the topic began to develop in 2016, with the publication of studies from the Johns Hopkins University School of Medicine in Baltimore Maryland, and the New York University Langone Medical Center in New York City which were hailed as potentially groundbreaking.

“This seems to be getting quite mainstream academic support,” he said.

Past research has shown that psychedelics work on the body’s serotonin system, particularly on the 5-HT2A receptors, which are highly cortical, Dr. Carhart-Harris explained. Recent research with a positron emission tomography (PET) agonist tracer added to that knowledge, showing that the expression of 5-HT2A receptors is especially high in high-level cortical regions of the brain and regions associated with the default mode network, which is linked with such high-level functions as introspection and imagination.

“It’s intriguing that these compounds that can have such a profound effect on consciousness have their key locus of action in such a high level aspect of the brain,” he said.

He noted that psychedelics, which have been used in some cultures for hundreds or thousands of years, have a more precise psychopharmacological approach than antidepressants developed in recent decades.

Dr. Carhart-Harris suggests that psychedelics work by relaxing aberrant beliefs which underlie a range of different psychopathologies, such as the pessimism common in depression. By inducing neural plasticity, they also provide a window of opportunity for revising those beliefs, he said.

Dr. Carhart-Harris argued that psychedelics are not addictive and are much more favorable in terms of toxicity than another emerging psychiatric treatment, ketamine. Users may experience headache, and about 5% have a residual effect on their perception, though only 1% are disturbed by it, he said. There have been concerns about psychedelics leading to psychotic episodes and disorders, but Dr. Carhart-Harris said that association is not supported by evidence.

—Terri Airov


“Psychedelics: therapeutic mechanisms & clinical findings.” Presented at Psych Congress 2018: Orlando, Florida; October 25, 2018.